Edy Laverde

## Explanation This PR adds suppor to slack messages with buttons inside the attachments https://api.slack.com/docs/message-buttons For the tests I take the example on https://api.slack.com/docs/message-buttons

According with the assertion this -> ``` javascript var date = new Date("11-3-2015"); ``` should be ``` javascript var date = new Date("11-3-2014"); ``` using version published on 2015-04-23